diff mbox series

[v7,3/3] docs/system: riscv: Add pflash usage details

Message ID 20230601045910.18646-4-sunilvl@ventanamicro.com (mailing list archive)
State New, archived
Headers show
Series hw/riscv/virt: pflash improvements | expand

Commit Message

Sunil V L June 1, 2023, 4:59 a.m. UTC
pflash devices can be used in virt machine for different
purposes like for ROM code or S-mode FW payload. Add a
section in the documentation on how to use pflash devices
for different purposes.

Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 docs/system/riscv/virt.rst | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

Comments

Alistair Francis June 1, 2023, 5:33 a.m. UTC | #1
On Thu, Jun 1, 2023 at 3:01 PM Sunil V L <sunilvl@ventanamicro.com> wrote:
>
> pflash devices can be used in virt machine for different
> purposes like for ROM code or S-mode FW payload. Add a
> section in the documentation on how to use pflash devices
> for different purposes.
>
> Signed-off-by: Sunil V L <sunilvl@ventanamicro.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>

Alistair

> ---
>  docs/system/riscv/virt.rst | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
>
> diff --git a/docs/system/riscv/virt.rst b/docs/system/riscv/virt.rst
> index 4b16e41d7f..b33f45e5b3 100644
> --- a/docs/system/riscv/virt.rst
> +++ b/docs/system/riscv/virt.rst
> @@ -53,6 +53,37 @@ with the default OpenSBI firmware image as the -bios. It also supports
>  the recommended RISC-V bootflow: U-Boot SPL (M-mode) loads OpenSBI fw_dynamic
>  firmware and U-Boot proper (S-mode), using the standard -bios functionality.
>
> +Using flash devices
> +-------------------
> +
> +By default, the first flash device (pflash0) is expected to contain
> +S-mode firmware code. It can be configured as read-only, with the
> +second flash device (pflash1) available to store configuration data.
> +
> +For example, booting edk2 looks like
> +
> +.. code-block:: bash
> +
> +  $ qemu-system-riscv64 \
> +     -blockdev node-name=pflash0,driver=file,read-only=on,filename=<edk2_code> \
> +     -blockdev node-name=pflash1,driver=file,filename=<edk2_vars> \
> +     -M virt,pflash0=pflash0,pflash1=pflash1 \
> +     ... other args ....
> +
> +For TCG guests only, it is also possible to boot M-mode firmware from
> +the first flash device (pflash0) by additionally passing ``-bios
> +none``, as in
> +
> +.. code-block:: bash
> +
> +  $ qemu-system-riscv64 \
> +     -bios none \
> +     -blockdev node-name=pflash0,driver=file,read-only=on,filename=<m_mode_code> \
> +     -M virt,pflash0=pflash0 \
> +     ... other args ....
> +
> +Firmware images used for pflash must be exactly 32 MiB in size.
> +
>  Machine-specific options
>  ------------------------
>
> --
> 2.34.1
>
>
diff mbox series

Patch

diff --git a/docs/system/riscv/virt.rst b/docs/system/riscv/virt.rst
index 4b16e41d7f..b33f45e5b3 100644
--- a/docs/system/riscv/virt.rst
+++ b/docs/system/riscv/virt.rst
@@ -53,6 +53,37 @@  with the default OpenSBI firmware image as the -bios. It also supports
 the recommended RISC-V bootflow: U-Boot SPL (M-mode) loads OpenSBI fw_dynamic
 firmware and U-Boot proper (S-mode), using the standard -bios functionality.
 
+Using flash devices
+-------------------
+
+By default, the first flash device (pflash0) is expected to contain
+S-mode firmware code. It can be configured as read-only, with the
+second flash device (pflash1) available to store configuration data.
+
+For example, booting edk2 looks like
+
+.. code-block:: bash
+
+  $ qemu-system-riscv64 \
+     -blockdev node-name=pflash0,driver=file,read-only=on,filename=<edk2_code> \
+     -blockdev node-name=pflash1,driver=file,filename=<edk2_vars> \
+     -M virt,pflash0=pflash0,pflash1=pflash1 \
+     ... other args ....
+
+For TCG guests only, it is also possible to boot M-mode firmware from
+the first flash device (pflash0) by additionally passing ``-bios
+none``, as in
+
+.. code-block:: bash
+
+  $ qemu-system-riscv64 \
+     -bios none \
+     -blockdev node-name=pflash0,driver=file,read-only=on,filename=<m_mode_code> \
+     -M virt,pflash0=pflash0 \
+     ... other args ....
+
+Firmware images used for pflash must be exactly 32 MiB in size.
+
 Machine-specific options
 ------------------------